This invention pertains to cooking equipment that uses water to either assist with cooking or as the main cooking medium. The cooking equipment which includes ovens commonly called xe2x80x9crotisseriexe2x80x9d ovens used in supermarkets to prepare quantities of food, includes components for the removal of grease that might otherwise interfere with the use of the water in the cooking equipment. The invention also pertains to a method for removing the grease.
Cooking equipment that uses water to either assist with cooking or as the main cooking medium typically includes a reservoir to contain the water within the equipment. In some cooking equipment. this reservoir resides within the bottom of the equipment to create a large surface of water from which water vapor is readily formed and/or to function as a drip pan. In cooking operations that deal with foodstuffs comprising or to which fats, oils or grease are added, as grease falls from the food stuff, a grease/water mixture results. Grease segregates from the water because of its immiscibility and floats to the surface of water because of its lower specific gravity or density to form slicks on the surface of the water in the reservoir. As the number and size of slicks increases, the quantity of water/vapor interfacial area decreases, which in turn can decrease the volume of water vapor in the equipment. When a grease film forms substantially over the entire surface of the water, rather than evaporating directly to water vapor, water must first diffuse through the grease film to sustain the water vapor within the equipment. However, it appears that rate of water diffusion through grease is insufficient to sustain the volume of water vapor in the equipment, thus the humidity or water vapor content in the equipment drops to unacceptable levels. There is a need for a solution to this problem.
In addition, the grease/water mixture, once drained form the cooking equipment can be problematic if disposed directly into a sewer line since the grease/water mixture burdens municipal sewer systems. In fact, municipal authorities surcharge businesses discharging grease/water mixtures directly into sewer lines connected to the municipal systems. The present invention may also be used to relieve the sewer rate surcharges by diverting the grease component from a grease/water mixture to dispose only a gray water into the municipal sewer line.
It is known to separate grease from water in cooking equipment using specific gravity or density differences between the grease and the water. Although such systems appear to be effective in separating grease from the water. they lack in their ability to maintain a constant humidity.
U.S. Pat. No. 2,097,793 discloses cooking by broiling. A device having a shallow vessel D with a tubular member 16 passing through the bottom of the shallow vessel D and ending a short distance below the bottom of the shallow vessel D is disclosed. The upper end of the tubular member 16 is preferably expanded to form a hollow cone. A drain hole by which the shallow vessel D may be drained, having plug 23 with a draw chain 21 is provided in the bottom of the shallow vessel D. A catch vessel F is placed underneath the lower end of the tubular member 16. The shallow vessel D is partly filled with water until the level is near that of the upper end of the tubular member 16. As heat drives greases and juices from an object being cooked S, grease fills into the shallow vessel D and floats on the water, forming a thin layer 26. This thin layer of grease 26 runs over the upper edge of the cone to be caught in the catch vessel F. No considerable accumulation of grease is possible as it continually drains from the shallow vessel D through the tubular member 16 into the catch vessel F.
U.S. Pat. No. 4,506,593 discloses an apparatus for the heating of food stuffs by means of a steam-air mixture as a heating medium. The apparatus has a device beneath the cooking space for draining of the condensate and food juices or fat out of the cooking space. In a first position, the device discharges water and condensate out of the cooking space through a discharge pipe into a siphon. In a second position, the device directs fat and food components into a fat collection pan. By these two positions, the device ensures that no fat or food components can run from the cooking space into the siphon.
U.S. Pat. No. 4,924,072 discloses an oven for food convection cooking with superheated steam, saturated steam, or hot air. The oven incorporates a microprocessor to control temperature, cooking time and oven humidity.
U.S. Pat. No. 5,101,714 discloses a cooking unit that uses liquids such as oil or water for cooking. After use, the liquids are collected on an inclined plane for recycling through filters to regenerate the liquids for another cooking cycle.
U.S. Pat. No. 5,184,540 discloses a cooking apparatus that may include a reduction trap disposed beneath a spit to recover the juices produced when cooking food on the spit. Details of the trap include a food juice drain at an elevation above a water level so that juices may be drained off the water.
U.S. Pat. No. 5,584,236 discloses a device for fat removal that permits the separation of a cooked meat from the liquid medium used for cooking. The separation of fat that has floated to the top of a broth is described.
It is very apparent that there is a need to provide a system that continuously removes grease from the surface of a water reservoir and that overcomes the above problems of the prior art. More specifically, there is a need for a system that continuously maintains a consistent humidity or water vapor content. It is also apparent that there is a need for a system that separates the grease component, which is latter appropriately disposed, from the gray water component, which is disposed into a drain or a sewer.
The present invention satisfies the need for an integrated system that not only provides a consistent humidity or water vapor content within an atmosphere of an oven but also provides for the separation or segregation of a grease component from a gray water component prior to discharging the grease/water mixture from the oven into drain or sewer line. The integrated system includes an oven containing a water reservoir in fluid communication with an overflow or surface drain. The present invention also satisfies the need for an oven that provides a consistent humidity or water vapor content within its atmosphere. The oven contains a water reservoir in fluid communication with an overflow or surface drain. A water supply is in fluid communication with the water reservoir, preferably, in such a manner that facilitates regulated and/or disciplined supply (e.g., initial providing and subsequent replenishing) of water to the water reservoir.
At the start of a cooking operation, the empty water reservoir is filled with water. Upon heating, the water evaporates, supplying humidity or water vapor to the atmosphere within the oven. A foodstuff, such as, for example, a meat, might at this stage be placed into the oven. As cooking starts and then proceeds, juices and/or grease exuding from the foodstuff fall into the water to initially form slicks of grease on the surface of the water reservoir. In time, the number and/or size of the slicks grows to such an extent and, possibly, into a layer, to substantially cover the surface of the water reservoir, hindering the contacting communication of the water surface with the atmosphere of the oven. This, in turn, may decrease the humidity or water vapor content in the atmosphere of the oven. To reestablish a substantially grease free surface, water is introduced into the water reservoir through a water supply line in a regulated and/or disciplined manner to urged the grease slicks or layer into the overflow or surface drain. Reestablishing a substantially grease free water surface, in turn, reestablishes the humidity or water vapor content of the atmosphere within the oven. The regulated and/or disciplined introduction of water into the water reservoir may continued throughout the cooking operation. Applicants contemplate that the introduction of water might be performed either in a manual or automated manner.
An example of an automated manner includes a controller having a timer in communication with at least one valve on the water supply line. The timer might then regulate the frequency and duration of the opening of the at least one valve. The timer might be mechanical, electromechanical, or electronic and the at least one valve would than be a compatible, optionally, corresponding, device.
Another example of an automated manner includes a humidity sensor within the oven and a controller in communication with the humidity sensor and the at least one valve on the water supply line. Here, the humidity sensor monitors the humidity or water vapor content within the atmosphere of the oven during a cooking operation to communicate a signal corresponding to a measured humidity value to the controller for comparison with a pre-selected humidity value. This pre-selected humidity value in one cooking operation might be a minimum humidity value while in an other cooking operation might be a maximum humidity value while in yet an other cooking operation might be both a minimum and a maximum humidity value. The pre-selected humidity value or values establish a humidity or water content operating window that is bounded by a minimum value and/or a maximum value for the atmosphere of the oven. In a case that the operating window is bounded by a minimum pre-selected humidity value, when the measured value falls below that minimum value, water is introduced into water reservoir in a manner to urge the grease from the surface of the water reservoir into the overflow or surface drain to reestablish a substantially grease free water surface.
In another aspect of the present invention, the grease/water mixture exiting the oven is diverted into a separator unit to separate the grease/water mixture into its grease component and its gray water component. The grease component is then directed to a collection vessel for subsequent appropriate disposal while the gray water is directed to a drain or a sewer.